1. Field of the Invention
This invention relates to cutter bits for machining the side surfaces of rotating work pieces.
2. Prior Developments
During the machining of metal work pieces metal chips of an unacceptable string-like character are continuously generated. In order to prevent such chips from interfering with the machining process it is necessary to break such chips into shorter sections. The necessary chip-cutting action, or chip-breaking action, is accomplished with a chip-breaker ledge located near the cutting tip in the path of the chip generated by the metal cutting operation.
Preferably the chip-breaker ledge is located relatively close to the cutting tip in order to achieve a better shearing force on the chip. If the chip-breaker ledge is located too far away from the cutting tip the portion of the chip between the cutting tip and the breaker ledge will bend so that the chip slides along the ledge rather than breaking off cleanly.
The requirement that the chip-breaker ledge be relatively close to the cutting tip presents a problem when the chip thickness is variable. If the chip-breaker ledge is located close enough to the curing tip to effectively break thin chips it may be too close to effectively handle thick chips; the thicker chip material may run into the breaker ledge while it is still attached to the work piece, such that the chip is crowded into the space between the cutting tip and the breaker ledge.
U.S. Pat. No. 2,903,781 discloses a machining system wherein the chip breaker is formed separately from the cutting insert. The chip-breaker element can be adjusted toward or away from the cutting tip for handling chips of varying thickness. However, the chip-breaker element cannot simultaneously handle chips of varying thickness. A set screw adjustment must be manually operated to accommodate the chip-breaker to different chip thicknesses; i.e. the chip breaker is set relatively close to the cutting tip for breaking relatively thin chips, and relatively far away from the cutting tip for handling relatively thick chips.